Geometrical modeling of complete dental shapes by using panoramic X-ray, digital mouth data and anatomical templates

Abstract

In the field of orthodontic planning, the creation of a complete digital dental model to simulate and predict treatments is of utmost importance. Nowadays, orthodontists use panoramic radiographs (PAN) and dental crown representations obtained by optical scanning. However, these data do not contain any 3D information regarding tooth root geometries. A reliable orthodontic treatment should instead take into account entire geometrical models of dental shapes in order to better predict tooth movements. This paper presents a methodology to create complete 3D patient dental anatomies by combining digital mouth models and panoramic radiographs. The modeling process is based on using crown surfaces, reconstructed by optical scanning, and root geometries, obtained by adapting anatomical CAD templates over patient specific information extracted from radiographic data. The radiographic process is virtually replicated on crown digital geometries through the Discrete Radon Transform (DRT). The resulting virtual PAN image is used to integrate the actual radiographic data and the digital mouth model. This procedure provides the root references on the 3D digital crown models, which guide a shape adjustment of the dental CAD templates. The entire geometrical models are finally created by merging dental crowns, captured by optical scanning, and root geometries, obtained from the CAD templates.

Computational design and engineering of polymeric orthodontic aligners

“…It is also worth noting that in this article, a multimodality imaging approach has been used by integrating optical and tomographic scanning. However, technical literature has recently faced the problem of retrieving root anatomies by combining panoramic and/or lateral radiographs, without involving tomographic scanning . This would bring to the reconstruction of complete tooth models, thus addressing questions regarding root movements, by exploiting minimally invasive imaging modalities.…”

“…However, technical literature has recently faced the problem of retrieving root anatomies by combining panoramic and/or lateral radiographs, without involving tomographic scanning. [45][46][47] This would bring to the reconstruction of complete tooth models, thus addressing questions regarding root movements, by exploiting minimally invasive imaging modalities. This research trend is justified by the fact that, in current orthodontic practice, both panoramic radiographs and lateral cephalograms are usually required for diagnostic purposes.…”

Evaluation of the impact of reference tooth morphology and alignment on model measurement accuracy

“…The measurement of digital models only transfers the contact measurement method on the original plaster model to the screen and presents it in a non-contact form (13). Although existing studies have explored the substitutability of digital models from different data sources, and the validity of model measurements, few studies have focused on the effect of a comprehensive view of the threedimensional (3D) tooth structure on measurement accuracy (7,14,15). No studies have analyzed and compared the effect of tooth axis direction and tooth alignment on measurement results.…”